content: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2012, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jfreechart/index.html
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
   * Other names may be trademarks of their respective owners.]
   *
   * ------------------------
   * PieLabelDistributor.java
   * ------------------------
   * (C) Copyright 2004-2008, by Object Refinery Limited and Contributors.
   *
   * Original Author:  David Gilbert (for Object Refinery Limited);
   * Contributor(s):   -;
   *
   * Changes
   * -------
   * 08-Mar-2004 : Version 1 (DG);
   * 18-Apr-2005 : Use StringBuffer (DG);
   * 14-Jun-2007 : Now extends AbstractPieLabelDistributor (DG);
   * 31-Mar-2008 : Fix bugs in label distribution (DG);
   *
   */
  
  package org.jfree.chart.plot;
  
  import java.util.Collections;
  
  /**
   * This class distributes the section labels for one side of a pie chart so
   * that they do not overlap.
   */
  public class PieLabelDistributor extends AbstractPieLabelDistributor {
  
      /** The minimum gap. */
      private double minGap = 4.0;
  
      /**
       * Creates a new distributor.
       *
       * @param labelCount  the number of labels (ignored).
       */
      public PieLabelDistributor(int labelCount) {
          super();
      }
  
      /**
       * Distributes the labels.
       *
       * @param minY  the minimum y-coordinate in Java2D-space.
       * @param height  the available height (in Java2D units).
       */
      @Override
      public void distributeLabels(double minY, double height) {
          sort();  // sorts the label records into ascending order by baseY
  //        if (isOverlap()) {
  //            adjustInwards();
  //        }
          // if still overlapping, do something else...
          if (isOverlap()) {
              adjustDownwards(minY, height);
          }
  
          if (isOverlap()) {
              adjustUpwards(minY, height);
          }
  
          if (isOverlap()) {
              spreadEvenly(minY, height);
          }
      }
  
      /**
       * Returns <code>true</code> if there are overlapping labels in the list,
       * and <code>false</code> otherwise.
       *
       * @return A boolean.
       */
      private boolean isOverlap() {
          double y = 0.0;
          for (int i = 0; i < this.labels.size(); i++) {
              PieLabelRecord plr = getPieLabelRecord(i);
              if (y > plr.getLowerY()) {
                  return true;
              }
              y = plr.getUpperY();
          }
          return false;
      }
  
      /**
       * Adjusts the y-coordinate for the labels in towards the center in an
       * attempt to fix overlapping.
       */
      protected void adjustInwards() {
          int lower = 0;
          int upper = this.labels.size() - 1;
          while (upper > lower) {
              if (lower < upper - 1) {
                  PieLabelRecord r0 = getPieLabelRecord(lower);
                  PieLabelRecord r1 = getPieLabelRecord(lower + 1);
                  if (r1.getLowerY() < r0.getUpperY()) {
                      double adjust = r0.getUpperY() - r1.getLowerY()
                                      + this.minGap;
                      r1.setAllocatedY(r1.getAllocatedY() + adjust);
                  }
              }
              PieLabelRecord r2 = getPieLabelRecord(upper - 1);
              PieLabelRecord r3 = getPieLabelRecord(upper);
              if (r2.getUpperY() > r3.getLowerY()) {
                  double adjust = (r2.getUpperY() - r3.getLowerY()) + this.minGap;
                  r3.setAllocatedY(r3.getAllocatedY() + adjust);
              }
              lower++;
              upper--;
          }
      }
  
      /**
       * Any labels that are overlapping are moved down in an attempt to
       * eliminate the overlaps.
       *
       * @param minY  the minimum y value (in Java2D coordinate space).
       * @param height  the height available for all labels.
       */
      protected void adjustDownwards(double minY, double height) {
          for (int i = 0; i < this.labels.size() - 1; i++) {
              PieLabelRecord record0 = getPieLabelRecord(i);
              PieLabelRecord record1 = getPieLabelRecord(i + 1);
              if (record1.getLowerY() < record0.getUpperY()) {
                  record1.setAllocatedY(Math.min(minY + height
                          - record1.getLabelHeight() / 2.0,
                          record0.getUpperY() + this.minGap
                          + record1.getLabelHeight() / 2.0));
              }
          }
      }
  
      /**
       * Any labels that are overlapping are moved up in an attempt to eliminate
       * the overlaps.
       *
       * @param minY  the minimum y value (in Java2D coordinate space).
       * @param height  the height available for all labels.
       */
      protected void adjustUpwards(double minY, double height) {
          for (int i = this.labels.size() - 1; i > 0; i--) {
              PieLabelRecord record0 = getPieLabelRecord(i);
              PieLabelRecord record1 = getPieLabelRecord(i - 1);
              if (record1.getUpperY() > record0.getLowerY()) {
                  record1.setAllocatedY(Math.max(minY
                          + record1.getLabelHeight() / 2.0, record0.getLowerY()
                          - this.minGap - record1.getLabelHeight() / 2.0));
              }
          }
      }
  
      /**
       * Labels are spaced evenly in the available space in an attempt to
       * eliminate the overlaps.
       *
       * @param minY  the minimum y value (in Java2D coordinate space).
       * @param height  the height available for all labels.
       */
      protected void spreadEvenly(double minY, double height) {
          double y = minY;
          double sumOfLabelHeights = 0.0;
          for (int i = 0; i < this.labels.size(); i++) {
              sumOfLabelHeights += getPieLabelRecord(i).getLabelHeight();
          }
          double gap = height - sumOfLabelHeights;
          if (this.labels.size() > 1) {
              gap = gap / (this.labels.size() - 1);
          }
          for (int i = 0; i < this.labels.size(); i++) {
              PieLabelRecord record = getPieLabelRecord(i);
              y = y + record.getLabelHeight() / 2.0;
              record.setAllocatedY(y);
              y = y + record.getLabelHeight() / 2.0 + gap;
          }
      }
  
      /**
       * Sorts the label records into ascending order by y-value.
       */
      public void sort() {
          Collections.sort(this.labels);
      }
  
      /**
       * Returns a string containing a description of the object for
       * debugging purposes.
       *
       * @return A string.
       */
      @Override
      public String toString() {
          StringBuilder result = new StringBuilder();
          for (int i = 0; i < this.labels.size(); i++) {
              result.append(getPieLabelRecord(i).toString()).append("\n");
          }
          return result.toString();
      }
  
  }
  